一、任務間通信
- 優先級郵箱隊列
概述
優先級郵箱隊列相對郵箱隊列來說，給郵件附加了一個優先級的概念，較高優先級的郵件會比較低優先級的郵件更快地被其他任務收到（本質上，郵箱隊列的底層數據容器是環形隊列，優先級郵箱隊列的底層數據容器是優先級隊列）。
API講解
編程實例
1、在tos_config.h中，配置優先級郵箱隊列組件開關TOS_CFG_PRIORITY_MAIL_QUEUE_EN：
#define TOS_CFG_PRIORITY_MAIL_QUEUE_EN 1u
2、編寫main.c示例代碼：
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "cmsis_os.h"
#include "stdio.h"
#include "tos_k.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/*
這裏演示了優先級郵箱隊列的使用，從sender任務中的邏輯可以看出來，依次post了三個mail，優先級按時間順序依次爲2、1、0（數值越高優先級越低）。如果是傳統的郵箱隊列，那個receiver應該是依次收到優先級爲2、1、0的郵件；但這是優先級郵箱隊列，因而receiver會按優先級順序收到這三個郵件，也就是依次收到優先級爲0、1、2的郵件。
*/
#define STK_SIZE_TASK_RECEIVER 512
#define STK_SIZE_TASK_SENDER 512
#define MAIL_MAX 10
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
k_stack_t stack_task_receiver[STK_SIZE_TASK_RECEIVER];
k_stack_t stack_task_sender[STK_SIZE_TASK_SENDER];
typedef struct mail_st {
char *message;
int payload;
} mail_t;
uint8_t mail_pool[MAIL_MAX * sizeof(mail_t)];
k_task_t task_receiver;
k_task_t task_sender;
k_prio_mail_q_t prio_mail_q;
extern void entry_task_receiver(void *arg);
extern void entry_task_sender(void *arg);
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
void entry_task_receiver(void *arg)
{
k_err_t err;
mail_t mail;
size_t mail_size;
while (K_TRUE) {
err = tos_prio_mail_q_pend(&prio_mail_q, &mail, &mail_size, TOS_TIME_FOREVER);
if (err == K_ERR_NONE) {
TOS_ASSERT(mail_size == sizeof(mail_t));
printf("receiver: msg incoming[%s], payload[%d]\n", mail.message, mail.payload);
}
}
}
void entry_task_sender(void *arg)
{
mail_t mail_0, mail_1, mail_2;
printf("sender: post a mail with priority 2\n");
mail_2.message = "priority 2";
mail_2.payload = 2;
tos_prio_mail_q_post(&prio_mail_q, &mail_2, sizeof(mail_t), 2);
printf("sender: post a mail with priority 1\n");
mail_1.message = "priority 1";
mail_1.payload = 1;
tos_prio_mail_q_post_all(&prio_mail_q, &mail_1, sizeof(mail_t), 1);
printf("sender: post a mail with priority 0\n");
mail_0.message = "priority 0";
mail_0.payload = 0;
tos_prio_mail_q_post(&prio_mail_q, &mail_0, sizeof(mail_t), 0);
}
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
tos_knl_init();
tos_prio_mail_q_create(&prio_mail_q, mail_pool, MAIL_MAX, sizeof(mail_t));
(void)tos_task_create(&task_receiver, "receiver", entry_task_receiver, NULL,
6, stack_task_receiver, STK_SIZE_TASK_RECEIVER, 0);
(void)tos_task_create(&task_sender, "sender", entry_task_sender, NULL,
5, stack_task_sender, STK_SIZE_TASK_SENDER, 0);
tos_knl_start();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
3、運行效果：
源碼鏈接：Git